Relationship between the Microstructure of the Welded Steel Plates and the Efficiency of Vibration Stress Relief

Welded components of low alloy steels are widely used in various applications. Stress reliving is very important to these welded structures. Vibration stress relief (VSR) is an relatively new method for this purpose. In this study, Q235 and Q345 steel plates were welded. Then they were treated by VSR. The microstructure of the welded lines were investigated and the residual stresses in two directions in these welded structures were measured. The difference of the efficiency of VSR on the two materials were investigate. It is found that, the decreasing amplitude of the residual stress in the Q235 welded structures significantly exceeded that in the Q345 welded structures. The grain size in the area near the weld lines is the main factor that affects the efficiency of the VSR treatment.

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Influence of Vibration Stress Relief (VSR) on the Residual Stress and Microstructure in Welded Plate of DH36 Low Alloy High Strength Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.924 ◽

2014 ◽

Vol 887-888 ◽

pp. 924-928 ◽

Cited By ~ 1

Author(s):

Shu Qi Li ◽

Hong Yuan Fang ◽

Xuesong Liu

Keyword(s):

Residual Stress ◽

High Strength Steel ◽

High Strength ◽

Stress Relief ◽

Steel Plates ◽

Widespread Application ◽

Oil Platforms ◽

Offshore Oil Platforms ◽

Transmission Electron ◽

Vibration Stress

Welded components of DH36 low alloy high strength steel are widely used in offshore oil platforms and ships building. Stress reliving treatments to these welded components is of great importance. Vibration stress relief (VSR) method is an novel technology to release stress in welded components. In this study, 10×200×1000mm DH 36 steel plates were welded and then treated by VSR for about 1 hour. After the treatment, the residual stress was decreased by 29-72% at the welded toe, where the highest residual stress occurs. The metallographic microstructure of the joint was not changed by VSR. Investigation by transmission electron microscope (TEM) revealed that the amount of dislocations was increased at the welded toe. We hope this study can provide theoretical and practical fundamentals for widespread application of VSR on welded offshore engineering components.

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TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170876 ◽

1994 ◽

Vol 52 ◽

pp. 628-629

Author(s):

J. Fang ◽

H. M. Chan ◽

M. P. Harmer

Keyword(s):

Residual Stress ◽

Single Phase ◽

Stress Relief ◽

Stress Recovery ◽

Surface Residual Stress ◽

Microscopic Mechanism ◽

Sic Particles ◽

Annealing Procedure ◽

The Difference ◽

Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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Quasi-static intergranular brittle fracture at 0.5 tm: A non-equilibrium segregation mechanism of sulphur embrittlement in stress-relief cracking of low-alloy steels

Acta Metallurgica ◽

10.1016/0001-6160(86)90021-0 ◽

1986 ◽

Vol 34 (7) ◽

pp. 1335-1349 ◽

Cited By ~ 20

Author(s):

I-Wei Chen

Keyword(s):

Brittle Fracture ◽

Stress Relief ◽

Low Alloy Steels ◽

Intergranular Brittle Fracture ◽

Alloy Steels ◽

Equilibrium Segregation ◽

Non Equilibrium

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Finite Element Simulation Analysis on Residual Stress Relief of 7075 Aluminum Alloy Ring

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1032.135 ◽

2021 ◽

Vol 1032 ◽

pp. 135-140

Author(s):

Shao Feng Wu ◽

Xiang Sheng Gao ◽

Xian Rang Zhang ◽

Han Jun Gao

Keyword(s):

Residual Stress ◽

Aluminum Alloy ◽

Simulation Analysis ◽

Material Model ◽

Stress Relief ◽

Isotropic Hardening ◽

7075 Aluminum Alloy ◽

Vibration Stress ◽

Structural Parts ◽

Creep Constitutive Model

Vibration stress relief (VSR) and thermal stress relief (TSR) are important method to eliminate the residual stress of structural parts. The thermal vibratory stress relief (TVSR) is a new method to decrease and homogenize the residual stress. Based on the stress relaxation tests and the equivalent vibration equation of modal analysis, the creep constitutive model and the bilinear isotropic hardening plasticity material model (BISO) are combined to establish the numerical simulation model of TVSR of 7075 aluminum alloy ring part. The simulation results show that four different initial blank residual stress levels are obtained after quenching process, and the residual stress elimination and homogenization effect of TSR and TVSR is better than that of VSR. TVSR has a better effect on both residual stress elimination and homogenization, and the residual stress relief rate can reach more than 20%.

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Impurities, segregation and creep embrittlement

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1980.0106 ◽

1980 ◽

Vol 295 (1413) ◽

pp. 265-278 ◽

Cited By ~ 44

Keyword(s):

Surface Segregation ◽

Rupture Life ◽

Boundary Segregation ◽

Impurity Content ◽

Stress Relief ◽

Published Data ◽

Low Alloy Steels ◽

Creep Ductility ◽

Internal Surfaces ◽

Alloy Steels

Reported studies of creep embrittlement in low alloy steels at 550 °C and of stress relief cracking at 700 °C show conflicting evidence for the importance of residual impurities. Calculations of the relative effects of impurities, through segregation to grain boundaries and also to the internal surfaces of cavities, show that rupture life and ductility can be affected. Auger electron spectroscopic measurements of these segregations in commercial ½CrMoV steels give the relative importance for all active elements. For stress relief cracking, the equilibrium surface segregation results agree with cracking measurements and allow extension to all important elements. Analysis of published data shows that, in practice, impurities are as important as microstructure in causing embrittlement, the most important impurities being, equally, tin, copper and arsenic. A similar analysis for creep shows that impurities are more important than microstructure with copper dominant and phosphorus and tin also detrimental. Here, the creep ductility falls but rupture life increases with impurity content, consistent with a model involving grain boundary segregation. The stress relief cracking and creep embrittlement are both sensitive to impurities but, involving different segregations, are dominated by different elements.

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Research on Vibration Stress Relief Based on FEM

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.42.35 ◽

2010 ◽

Vol 42 ◽

pp. 35-38

Author(s):

Chun Mei Li ◽

Feng Kui Cui

Keyword(s):

Residual Stress ◽

Finite Elements ◽

Stress Distribution ◽

Stress Relief ◽

Residual Stress Distribution ◽

Exciting Force ◽

Finite Elements Method ◽

Machining Process ◽

Exciting Frequency ◽

Vibration Stress

In order to improve VSR(Vibration Stress Relief) effect, finite elements method is applied to study VSR process factors. Simulation on moulding process, rough machining process and heat treatment are used to study the residual stress distribution of casting. The modal analysis is carried out to determine exciting frequency, exciting position and support position. Based on residual stress distribution, harmonic response analysis is applied to find relationship between dynamic stress and exciting force. Then the exciting force can be determined. The research results indicate that finite elements method can be used to determine VSR process parameters quickly and accurately.

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Residual Stress Relief for 2219 Aluminum Alloy Weldments: A Comparative Study on Three Stress Relief Methods

Metals ◽

10.3390/met9040419 ◽

2019 ◽

Vol 9 (4) ◽

pp. 419 ◽

Cited By ~ 3

Author(s):

Shu-Guang Chen ◽

Yi-Du Zhang ◽

Qiong Wu ◽

Han-Jun Gao ◽

Dong-Yang Yan

Keyword(s):

Residual Stress ◽

Aluminum Alloy ◽

Longitudinal Direction ◽

Stress Relief ◽

The Other ◽

Good Effect ◽

Stress Release ◽

Maximum Reduction ◽

Vibration Stress ◽

2219 Aluminum Alloy

Thermal stress relief (TSR), vibration stress relief (VSR), and thermal and vibratory Stress relief (TVSR) have all been proven to be effective for residual stress relief. So far, no comparison has been made between the effects on residual stress relief of these three stress release methods. In this study, twelve 2219 aluminum alloy welding samples were divided into four groups. One of the groups is used as a reference without any stress relief treatment. The other three groups were processed by TSR, VSR, and TVSR, respectively. The residual stresses of depths of 0–1.2 mm are measured. Results show that small and uniform stresses are observed in the 2219 aluminum alloy welding samples after TSR, VSR, and TVSR treatment. TSR treatment decreased the peak residual stress much more than VSR and TVSR treatment. The maximum reduction of the peak residual stress is 50.8% (210 °C) in the transversal direction and 42.02% (185 °C) in the longitudinal direction after TSR treatment with the temperature range 140 °C to 210 °C. In terms of residual stress homogenization, although the TSR treatment has an advantage perpendicular to the weld direction, the effect parallel to the weld direction is not ideal. The TVSR has a good effect in both directions.

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Thermo-Mechanical Numerical Analysis in Steel Plates Butt Welded

Volume 3: Design and Analysis ◽

10.1115/pvp2014-28739 ◽

2014 ◽

Author(s):

Manuel Martinez ◽

Marco Gonzalez ◽

Antonio Barragan

Keyword(s):

Residual Stress ◽

Thick Plate ◽

Transient State ◽

3D Models ◽

Steel Plates ◽

Welded Steel ◽

Structural Part ◽

Structural Responses ◽

Two Stages ◽

2D And 3D

In this work, 2D and 3D Finite Element models to simulate the temperature distribution and residual stress in butt-welded steel plates with the aid of computer simulation, using the commercial software Abaqus®, are developed. The work is carried out in two stages: 1) An analysis of heat transfer in transient state regardless of the structural part is performed, and 2) Thermal and structural responses are sequentially coupled in a thermo-mechanical process simulation in order to determine the final residual stresses induced during progressive heating and subsequent cooling. The results show that for 2D and 3D models the residual stress distribution for relatively thick plate welding can be characterized by a state of stresses plane, dominated by longitudinal stresses. The main difference between both models occurs for transverse stress σY where the values for 3D are significantly greater than for 2D.

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Environmental Cracking Susceptibility of Low-Alloy Steels Under a High H2S Pressure and High-Temperature Sour Environment

CORROSION ◽

10.5006/2669 ◽

2017 ◽

Vol 74 (5) ◽

pp. 509-519 ◽

Cited By ~ 2

Author(s):

Kenji Kobayashi ◽

Tomohiko Omura ◽

Atsushi Souma ◽

Taro Ohe ◽

Hisashi Amaya ◽

...

Keyword(s):

High Temperature ◽

Localized Corrosion ◽

Low Alloy Steels ◽

Stress Cracking ◽

Partial Pressures ◽

Sulfide Stress ◽

Alloy Steels ◽

The Difference ◽

Grade Material ◽

Point Bend

Environmental cracking (EC) susceptibility of low-alloy steels with a specified minimum yield strength of 655 MPa (95 ksi) and 758 MPa (110 ksi) manufactured by quenching and tempering heat treatments was investigated in high H2S partial pressures (more than 1.0 MPa) using four-point bend tests in autoclaves. The H2S partial pressures and testing temperatures varied from 1.0 MPa to 10 MPa and 24°C to 150°C, respectively. Materials of grades 95 ksi and 110 ksi containing high Cr and Mo showed no macrocracking under all tested conditions. Localized corrosion occurred at several locations after exposure for 1 month under high H2S pressure and high-temperature conditions. It was concluded that the localized corrosion did not form macrocracking even after long-term (3 months) immersion tests. On the other hand, 110 ksi grade material containing low Cr and Mo suffered from sulfide stress cracking at low temperatures (below 66°C) and at an H2S pressure of 1.0 MPa. The material also showed EC at an H2S pressure of 10 MPa and temperature from 107°C to 150°C. The difference of EC susceptibility among the materials is discussed based on corrosion reactions, hydrogen absorption, and morphologies of the corrosion products on the steel surface.

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